Covered conductor and heater formed therewith

ABSTRACT

There is disclosed a conductor having a conductive element and a covering surrounding at least a portion of the conductive element. Preferably, the covering has an inner portion and an outer portion formed of different materials such that the melting point of the inner portion is higher than the melting point of the outer portion. The conductor is particularly useful for forming heaters, which may be integrated into a seat of an automotive vehicle.

FIELD OF THE INVENTION

[0001] The present invention relates generally to covered (e.g., coated)conductors and more particularly to covered conductors for use inheating systems of automotive vehicle seats or other articles ofmanufacture.

BACKGROUND OF THE INVENTION

[0002] For many years, industry has been concerned with designingimproved conductors for various articles and applications. As anexample, industry has designed conductors suitable for integration intoheaters, which may be employed in seats of automotive vehicles forproviding heat to passengers within those vehicles. In the interest ofcontinuing such innovation, the present invention provides a conductor,which may be suitable for various applications, but which has foundparticular utility in heaters that may be integrated within seats ofautomotive vehicles.

SUMMARY OF THE INVENTION

[0003] According to one aspect of the invention, there is disclosed aconductor and a method of forming the same. The conductor is formed byproviding a conductive element and applying a coating to the conductiveelement. Typically, the coating includes at least a portion that has arelatively low melting point. According to one preferred embodiment, theconductor has an inner portion with a first melting point and an outerportion with a second melting point that is relatively low compared tothe first melting point.

[0004] According to another aspect of the invention there is provided aheater and a method of forming the same. The heater is formed byproviding a conductor as described above and contacting that conductorwith a substrate. During such contact, the relatively low melting pointportion of the coating of the conductor is softened by heating andintegrated with the substrate. Thereafter, the relatively low meltingpoint portion of the coating is hardened by cooling thereby attachingthe conductor to the substrate.

[0005] According to still another aspect of the invention there isprovided a seat for an automotive vehicle and a method of forming thesame. The seat is formed by providing a heater as just described andintegrating that heater into the seat.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The features and inventive aspects of the present invention willbecome more apparent upon reading the following detailed description,claims and drawings, of which the following is a brief description:

[0007]FIG. 1 is a sectional view of a conductor in accordance with oneexemplary aspect of the present invention;

[0008]FIG. 2 is a sectional view of another exemplary conductor inaccordance with the present invention;

[0009]FIG. 2A is a sectional view of another alternative exemplaryconductor in accordance with the present invention;

[0010]FIG. 3 is a top view of one illustrative heater element useful inaccordance with the present invention; and

[0011]FIG. 4 is a partially cut away perspective view of a seat of anautomotive vehicle seat assembly in accordance with an exemplary aspectof the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention is predicated upon providing an improvedcoated conductor. It is contemplated that the conductor may be employedin a variety of articles of manufacture including, without limitation,electronic articles such as door panels, wheels, floormats, radios,televisions, calculators, computers or the like. The conductor, however,is particularly suitable for use in heaters and even more particularly,the conductor is suitable for use in heater systems of seats for use inautomotive vehicles.

[0013] According to one aspect, the conductor of the present inventionis provided with a covering (e.g., a coating) wherein at least a portionof the covering is activatable (e.g., has a relatively low meltingpoint). Advantageously, it is possible, although not necessarilyrequired, that the portion of the covering that is activatable (e.g.,has the relatively low melting point) may be activated (e.g., heated andsoftened) such that the softened portion can integrate itself with asubstrate for attaching the conductor to the substrate. Upon cooling itwill preferably re-harden and attach to the substrate.

[0014] Referring to FIG. 1, there is illustrated a schematic diagram ofa conductor 10 in accordance with one aspect of the present invention.The conductor 10 includes a conductive element 12 and a covering 14(e.g., a coating) disposed over at least a portion of the conductiveelement 12. As shown, the covering 14 is in direct contact with asurface 20 of the conductive element 12, however, it is contemplatedthat one or more intermediate layers may be disposed between thecovering 14 and the conductive element 12, over some or all of theconductive element.

[0015] As used herein, the term conductive element 12 is used to referto any medium capable of carrying an electrical charge, conducting heator electricity or a combination thereof. Accordingly, the conductiveelement 12 may be provided in several different shapes, sizes,configurations or the like. As examples, the conductive element 12 maybe provided as one or a plurality of plates, blocks, strands, tapes,sheets, weavings, deposited traces (e.g., electrochemically depositedtraces, vapor deposited traces) of combinations thereof. The shape ofthe element may be straight, arcuate, planar, helical, woven, twisted,wound, contoured, geometric, combinations thereof or the like.Furthermore, it is contemplated that the conductive element 12 may beformed as a single component (e.g., as a single wire) or as multiplecomponents (e.g., as a plurality of wires wound or twisted together,axially aligned, or otherwise integrated with each other). It is alsocontemplated that the conductive element may include a plurality ofgenerally parallel spaced apart wires such as for ribbon cables or thelike.

[0016] The conductive element may also be formed of a variety ofmaterials. Such materials may include metals, plastics, polymericmaterials, elastomers, glass and optical materials, organic materials,inorganic materials combinations thereof or the like. Exemplary metals,which may partially or fully compose the conductive element include,without limitation, copper, aluminum, silver, tin, tungsten, gold,platinum or the like. Exemplary polymeric materials, which may partiallyor fully compose the conductive element include conductive polymers suchas polyaniline, conjugated polymers, doped polymers, combinationsthereof or the like. In one embodiment, the conductive element may beprovided as a polymeric material having a dispersion of metal or carbonblack.

[0017] The covering 14, like the conductive element 12, may be formed ina variety of different shapes, sizes and configurations. Thus, thecovering may be planar, contoured, continuous, discontinuous (e.g.intermittent, porous, or the like) or combinations thereof. Preferably,the covering 14 forms a layer upon the conductive element 12 wherein thelayer has a substantially uniform thickness, however, a variablethickness is also contemplated within the scope of the presentinvention.

[0018] It is also contemplated that the coating is so formed relative tothe conductive element that some of the material is disposed in theinterstices of separate filaments of the conductive element.

[0019] According to one embodiment, the covering 14 may be formed of asingular homogeneous material. For such an embodiment, the meltingtemperature of the homogeneous material is typically between about 40°C. or lower and about 275° C. or higher, more preferably it is betweenabout 90° C. and about 180° C., even more preferably it is between about110° C. and about 160° C.

[0020] While one embodiment contemplates a homogeneous composition ofthe coating material throughout the covered conductor, generally, it ispreferable for the covering 14 to very in composition at locationsacross a section or along the covered conductors length. As an example,the composition of the covering 14 will exhibit a gradient across aportion of the covering 14 (e.g., from the conductive element 12 to anouter surface 28 of the covering 14). This can be achieved byintroducing a gradient within a single coating layer. It may be achievedby employing a plurality of layers, each an individual substantiallyhomogeneous layer, or having one or more non-homogeneous layers.

[0021] By way of example, referring to FIG. 1, one preferred covering 14is formed of a first portion 34 and a second portion 36 with bothportions being formed of compositionally different materials.Preferably, the materials are selected of the first portion 34 does notsubstantially intermix with the material of a second portion 36. As aresult, each of the portions 34 and 36 are able to remain substantiallydiscrete from each other. Of course it is contemplated that some orsubstantial intermixing or interdiffusion of the materials may occur incertain situations, particularly at the interface 38 of portions 34, 36.

[0022] While no particular thickness are required for the portions 34,36 of the covering, it is contemplated that, particularly forapplication within heaters, the portions 34, 36 be relatively thin. Asexamples, the thickness of the inner portion 34 or the thickness ofsingular homogeneous covering is preferably between about 0.001 inchesor lower and about 0.1 inches or higher, more preferably between about0.005 inches and about 0.05 inches and even more preferably betweenabout 0.0075 inches and about 0.025 inches. Exemplary thicknesses forthe outer portion 36 are preferably between about 0.0001 inches or lowerand about 0.03 inches or higher, more preferably between about 0.001inches and about 0.01 inches and even more preferably between about0.0025 inches and about 0.0075 inches.

[0023] In a preferred embodiment, the compositions of the first portion34 and the second portion 36 are such that the material of the innerportion 34 has a higher melting point than the material of the outerportion 36. For example, the melting point of the inner portion 34 ispreferably between about 10° C. and about 200° C., more preferablybetween about 30° C. and about 150° C. and even more preferably betweenabout 40° C. and about 120° C. greater than the melting point of theouter portion 36.

[0024] The actual melting point of the inner portion 34 is preferablybetween about 80° C. or lower and about 400° C. or higher, morepreferably between about 110° C. and about 330° C., even more preferablybetween about 170° C. and about 275° C. The actual melting point of theouter portion 36 is preferably between about 40° C. or lower and about275° C. or higher, more preferably between about 90° C. and about 180°C., even more preferably between about 110° C. and about 160° C.

[0025] The covering 14 is preferably formed of one or more polymericmaterials, which may include plastics, thermoplatics, elastomers,combinations thereof or the like. Exemplary materials include, withoutlimitation, silicon, polytetrafluoroethylene (PTFE), polyvinylchloride(PVC), polypropylene, high density polyethylene (HDPE), low densitypolyethylene (LDPE), fluorinated or chlorinated polyethylene,fluoroethylene propylene, polyfluoroethylen (PFE), combinations thereofor the like. It is contemplated that the materials mentioned orcombinations thereof may be used as the material for a singular materialhomogeneous covering or a non-homogeneous covering (e.g., a coveringhaving two or more substantially separate portions).

[0026] Referring to FIG. 2, there is illustrated one exemplary conductor50 formed in accordance with an aspect of the present invention. In FIG.2, the conductor 50 is a wire that is illustrated in cross-section. Theconductor 50 includes a conductive element 52 that is comprised of aplurality (e.g., six) of metal strands 54 assembled together. Optionallythe strands may be assemble about an insert 56, which is formed ofKEVLAR® or another material. The conductive element 52 is substantiallyentirely surrounded by a covering 58. In the embodiment depicted, thecovering 58 includes an inner portion 60, which is generally annular andsubstantially entirely surrounds the conductive element 52. The covering58 further includes an outer portion 64 substantially entirelysurrounding the inner portion 60 and the conductive element 52. In theembodiment illustrated, the inner portion 60 directly contacts theconductive element 52 and the outer portion 64 directly contacts theinner portion 60 although such is not necessarily required.

[0027] In the exemplary embodiment, the inner portion 60 of the covering58 is formed of fluoroethylene propylene and is about 0.005 inches thickand has a melting temperature between about 185° C. and about 215° C.The outer portion 64 of the covering 58 is formed of polyethylene and isabout 0.010 inches thick and has a melting temperature between about 90°C. and about 115° C. The strands 54 of the conductive element 52 arethirty eight gage and are formed of a tin/copper material with aresistance of about 0.32 ohms. Moreover, the final outside diameter ofthe conductive element 52 is about 0.0365 inches.

[0028] Referring to FIG. 2(a), there is illustrated another exemplaryembodiment of a conductor 70 in accordance with the present invention.As shown the conductor 70 of FIG. 2(a) includes the same conductiveelement 52 as the conductor 50 of FIG. 2. However, the conductor 70includes a covering 72 formed of a singular homogeneous material. Inparticular, the entire covering 72 is formed of the polyethylenematerial that is used to form the outer portion 64 of the conductor 50of FIG. 2(a).

[0029] Manufacture of the conductor of the present invention typicallyincludes application of the covering to the conductive element. Theskilled artisan will recognize that many techniques may be employed forapplying the covering to the conductive element. For instance, thecovering may be brushed, dabbed, painted, poured, pressed, extruded orotherwise placed upon the conductive element to partially orsubstantially fully cover or coat the conductive element. Alternatively,it is contemplated that the conductive element may be submerged in abath of substantially molten covering material. Moreover, for conductorswith covering having multiple portions of different materials, it iscontemplated that the covering may be applied in stages (e.g.,application of one material to form a first portion followed byapplication of a second different material to form a second portion).

[0030] For forming the embodiment of FIG. 2, the conductive element 52may be passed through an extruder such that the extruder coats theconductive element 52 with molten material of the inner portion 60followed by allowing the molten material to cool, cure, harden or acombination thereof for forming the inner portion 60. Thereafter, theconductive element 52 and the inner portion 60 may be passed togetherthrough either the original extruder or another extruder such that oneof these extruders coats the inner portion 60 with molten material ofthe outer portion 64 followed by allowing the molten material to cool,cure, harden or a combination thereof for forming the second portion 64.

[0031] As previously discussed, it is contemplated that the conductor ofthe present invention may be employed in a variety of articles ofmanufacture and may operate in a variety of capacities. The conductor ofthe present invention, however, has found particular utility for use inheaters. According to one embodiment, the conductor is attached to asubstrate for forming a heater or at least a portion thereof.

[0032] The conductor may be attached to a wide variety of substrates forforming a heater and the type of substrate will often depend upon thetype of heater desired. Exemplary substrates include fabrics, panels,members, combinations thereof or the like. Moreover, various materialsmay be employed for forming the substrate. For example, the substratemay be formed of fibrous materials, polymeric materials, metals,combinations thereof or the like In preferred embodiments, the substrateis formed of a fleece material, a gauze material, a felt material orcombinations thereof.

[0033] For attaching the conductor to the substrate, various attachmentsmay be employed such as adhesives, fasteners, combinations thereof orthe like. It is also contemplated that the conductor may beinterferingly attached to the substrate such as by interweaving theconductor with the substrate. As yet another alternative, a portion ofthe covering of the conductor may activate (e.g., soften or melt) andadhere itself to or integrate itself with the substrate. For example,the temperature of the covering of the conductor may be elevated byheating the covering such that one or more portions (e.g., the portionshaving lower melting points) are softened for allowing the covering tointegrate itself with the substrate followed by lowering the temperatureof the covering such that the covering hardens and attaches itself andthe conductor to the substrate.

[0034] As an example, it is contemplated that a heated member (e.g., aheated plate) may be contacted with the substrate of the heater whilethe substrate is contacted with the conductor. In turn the heated memberconveys energy to the substrate, which conveys energy to the coveringthereby softening the covering. In this manner, the softened covering isintegrated with the substrate followed by lowering the temperature ofthe covering such that the covering hardens and attaches itself and theconductor to the substrate.

[0035] Referring to FIG. 3, there is illustrated an exemplary heater 80formed in accordance with an aspect of the present invention. Forforming the heater 80, a substrate 82 is provided and a conductor itattached thereto. For exemplary purposes, the conductor 50 of FIG. 2 hasbeen attached to the substrate 82 although, it shall be understood thatany of the conductors discussed herein may also be used.

[0036] The substrate 82 is preferably a fabric material that is providedas a sheet or panel. Preferred fabric materials include fleecematerials, felt materials, combinations thereof or the like. Theconductor 50 is then arranged (e.g., patterned) upon the substrate 82 ina desired configuration. In FIG. 2, the conductor 50 is patterned in aserpentine manner and forms two undulating pathways 86 that are in alateral or side-by-side relationship with each other. It shall beunderstood, however, that the conductor 50 may be patterned upon thesubstrate 82 in a myriad of configurations within the scope of thepresent invention.

[0037] For attaching the conductor 50 to the substrate 82, energy (e.g.,heat) is preferably applied to the covering 58 of the conductor 50 forheating and at least partially softening (e.g., melting) at least theouter portion 64 of the covering 58 and preferably substantially onlythe outer portion 64 of the covering 58. Although, such energy may beapplied according to different techniques, it is preferable for theparticular example shown that such energy be applied by flowing anelectrical current through the conductive element 52 for heating theelement and the covering 58.

[0038] As the outer portion 64 of the covering 58 softens, the portion64 preferably integrates itself with the substrate 82 such as by flowinginto the substrate 82, wetting a portion or surface of the substrate 82,combinations thereof or the like. After integration of the outer portion64 of the covering 58 with the substrate 82, the portion 64 of thecovering 58 is preferably allowed to cool and harden (e.g., solidify)thereby attaching (e.g., adhering) the conductor 52 to the substrate 82for forming the heater 80. If desired, a plate or other member may beemployed to place pressure or force upon the substrate 82, the conductor50 or both for urging the substrate 82 and conductor 50 into moreintimate contact during integration of the covering 58 with thesubstrate 82.

[0039] Advantageously for the conductor of FIG. 2, the melting point ofthe inner portion 60 of the conductor 50 is typically higher than themelting point of the outer portion 64 of the conductor 50 such that theheating of the covering 58 only substantially softens the outer portion64 of the conductor 50 without substantially softening the inner portion60. This allows the outer portion 64 of the conductor 50 to attach tothe substrate without risking substantial repositioning or other damageof the conductive element 52, the inner portion 60 or both.

[0040] It should be understood that while use of materials withpre-selected melting points is one preferred method of providing acovering that will attach itself to a substrate, it is also contemplatedthat other methods may be employed as well. In particular, it iscontemplated that a covering may be configured to activate (e.g.,soften) and integrate itself within a substrate by various methods. Forexample, a covering may be activated by exposure to a condition such asheat, pressure, moisture, heat or the like to chemically or otherwisephysically activate or soften.

[0041] Vehicle Seat

[0042] With regard to heaters formed with the conductor of the presentinvention, it has been found that heaters such as the heater 80 of FIG.3 are particularly suitable for integration to seats of automotivevehicles. Of course, conductors and heaters formed according to thepresent invention find utility in other articles of manufacture such asboats, furniture or the like as well.

[0043] A heater according to the present invention may be located invarious portions of an automotive vehicle seat such as a supportportion, a backrest portion, a shoulder support portion or a headrest.The heater may be located between the trim of the seat and the foamcushioning of the seat. The heater may also be integrated into the trimof the seat, the foam cushioning of the seat or both.

[0044] Referring to FIG. 4, a seat 90 of an automotive vehicle isillustrated wherein the heater 80 of FIG. 3 has been placed in both aseat backrest component 92 and a seat support component 94. In theembodiment illustrated, each component 92, 94 of the seat 90 includes atrim layer 96 and a foam cushion 98 and each of the heaters 70 ispositioned substantially between the foam cushion 98 and trim layer 96.Preferably, each heater 70 is fastened to the seat 90 (e.g., the trimlayer 96, the cushion 98 or both) for maintaining the heater 80stationary relative to the seat 90.

[0045] In operation, a temperature regulation unit may be employed inconjunction with the heater 80. For example, a temperature regulationunit may include a controller and a thermostat configured formaintaining desired temperatures during heating.

[0046] Unless stated otherwise, dimensions and geometries of the variousstructures depicted herein are not intended to be restrictive of theinvention, and other dimensions or geometries are possible. Pluralstructural components can be provided by a single integrated structure.Alternatively, a single integrated structure might be divided intoseparate plural components. In addition, while a feature of the presentinvention may have been described in the context of only one of theillustrated embodiments, such feature may be combined with one or moreother features of other embodiments, for any given application. It willalso be appreciated from the above that the fabrication of the uniquestructures herein and the operation thereof also constitute methods inaccordance with the present invention.

[0047] The preferred embodiment of the present invention has beendisclosed. A person of ordinary skill in the art would realize however,that certain modifications would come within the teachings of thisinvention. Therefore, the following claims should be studied todetermine the true scope and content of the invention.

What is claimed is:
 1. A heater comprising: a substrate substantiallyconfigured as a panel; and a conductor patterned over at least onesurface of the substrate, the conductor including: i) a conductiveelement; and ii) a covering substantially surrounding the conductiveelement, at least a portion of the covering being activatable uponexposure to a condition; wherein the coating is integrated into thesubstrate for attaching the conductor to the substrate.
 2. The heater ofclaim 1 wherein the conductive element includes multiple metal strands.3. The heater of claim 2 wherein the multiple metal strands at leastpartially surround an insert.
 4. The heater of claim 1 wherein thecondition that activates the covering is heat and the conductive elementis capable of emitting an amount of heat sufficient to activate thecovering.
 5. The heater of claim 1 wherein the covering is a polymericmaterial that coats the conductive element.
 6. The heater of claim 1wherein the substrate is formed of a flexible material.
 7. The heater ofclaim 6 wherein the substrate is formed of a fabric material selectedfrom the group consisting of fleece, gauze and felt.
 8. The heater ofclaim 1 wherein the covering has a substantially uniform thickness andthe uniform thickness is between about 0.001 inches and about 0.1inches.
 9. The heater of claim 8 wherein the thickness is between about0.005 inches and about 0.05 inches.
 10. A heater comprising: a substratesubstantially configured as a panel wherein the substrate is formed of aflexible material; and a conductor patterned over at least one surfaceof the substrate, the conductor including: i) a conductive element; andii) a covering substantially surrounding the conductive element, thecovering having an inner portion and an outer portion, the inner portionhaving a melting point between about 80° C. and about 400° C., the outerportion having a melting point between about 40° C. and about 275° C.;wherein the covering is integrated into the substrate for attaching theconductor to the substrate.
 11. The heater of claim 10 wherein theconductive element includes multiple metal strands.
 12. The heater ofclaim 11 wherein the multiple metal strands at least partially surroundan insert.
 13. The heater of claim 10 wherein the conductive element iscapable of emitting an amount of heat sufficient to soften the outerportion of the covering.
 14. The heater of claim 10 wherein the coveringincludes a polymeric material that coats the conductive element.
 15. Theheater of claim 10 wherein the substrate is formed of a fabric materialselected from the group consisting of fleece, gauze and felt.
 16. Theheater of claim 10 wherein the inner portion of covering has asubstantially uniform thickness and the uniform thickness is betweenabout 0.001 inches and about 0.1 inches.
 17. The heater of claim 16wherein the thickness is between about 0.005 inches and about 0.05inches.
 18. A heater comprising: a substrate substantially configured asa panel, the substrate being formed of a flexible fabric material; and aconductor patterned over at least one surface of the substrate, theconductor including: i) a conductive element formed of a metal materialand configured to emit heat; and ii) a coating substantially surroundingthe conductive element, the coating having an inner portion and an outerportion, the inner portion having a melting point between about 170° C.and about 275° C., the outer portion having a melting point betweenabout 110° C. and about 160° C.; wherein the conductive element iscapable of emitting sufficient heat to raise a temperature of the outerportion of the coating to the melting point of the outer portion; andwherein the covering is integrated into the substrate for attaching theconductor to the substrate.
 19. The heater of claim 18 wherein the outerportion and the inner portion of the coating are formed of a polymericmaterial.
 20. The heater of claim 19 wherein the polymeric material ofthe outer portion includes a polymeric material selected from the groupconsisting of PTFE, PVC, polyproylene, HDPE, LDPE, chlorinatedpolyethylene and fluorinated polyethylene.